Polyurethane Foam as a supplement to live rock

[00Stoll]

Hey all.

I'm re-entering the hobby after an 8 year break and am currently setting up a 90 gal reef with a 30 gal refugium/sump. I was flipping through my copy of Delbeek and Sprung's "The Reef Aquarium" and came across this passage:

Some large public and private reef aquariums in Europe have very little limestone rock at all in them. What looks like rock in these tanks is actually a polyurethane foam substance which has been shaped to look like rock. The surface is apparently very attractive to coralline algae which rapidly colonize it, making it virtually indistinguishable from the "real McCoy."​

They say that they don't know much about it, and that they would be cautious about using it since it could leach toxic compounds, but then they back off of that, noting that major aquariums have had success.

Have any of you tried anything like this? Foam would certainly be a less expensive, more reef-friendly material than natural reef rock. It could even be kept mostly out of sight behind a facade of real live rock. It would also provide a cleaner refugium if macro-algae would attach to it.

Thoughts?

-Alec

 

[dunc101]

I "think" you might be talking about the spray foam that people use to create "rock" backgrounds. Do a google for spray foam reef backgrounds and you'll get a ton of threads on it =). They look very nice if done correctly.

 

[tippmannsniper]

When the foam is still wet, grab some rubble rock and/or sand and lightly press it into the background.. it will help make the environment appear more natural and give you somewhere to attack some corals

 

[Humu Humu]

As long as it's non-toxic and has a lot of surface area, it probably would work well. I think J. Sprung was the first to move away from live rock.

You just need the surface area for the bacteria to colonize.

 

[00Stoll]

Thanks

Thanks

Thanks for the info. Some of the Spray Foam backgrounds are amazing to look at! How much good do you think it does as a habitat for bacteria? My memory of the stuff is that it's really porous, especially if you break up the finish a little, the way the rock salt does.

Thanks again!

-Alec

 

[SantaMonica]

If you use a lot, make sure it has a really good attachment/anchor or else it might float away.

 

[HippieSmell]

That type of foam is almost certainly closed cell, and won't have anywhere near the surface area as live rock. An open cell spray foam, if it exists, would be much better.

 

[kissman]

One problem I have seen that people have had was at some point it begins to break down and falls apart. Not sure how true it is but might want to look into it

 

[MrIcky]

If you are using the pond spray foam, it is aquarium safe, uv stable, and doesn't appear to break down (I know of some applications that are 5+ years old, I personally have used some for 2+ and it is very durable). There were problems with the spray foam that is basically insulation. Personally I used Beckett's but there are other similar brands.

 

[Kuniak13]

Can you use the spray foam to shape and stick live rock together. Like making an arch out of live rock by using the foam to stick them together

 

[MrIcky]

Kuniak13, the foam requires some curing time outside the tank. It will hold live rocks together but they might not be live by the time you're done curing the foam. Personally I used it on reefcleaners dry rock.

It's absolutely strong enough to make a moderate arch out of. I'm not sure I'd want much more than 25 lbs suspended without adding doweling though. If the structure is basically self supporting and you are securing it, then the foam works very well. My experience is the foam is much stronger than epoxy. I've tried to break apart rocks bonded by foam and the rocks were breaking before the foam did.

.

 

[KafudaFish]

http://www.reefcentral.com/forums/showthread.php?t=1438807&highlight=foam

 

[rickcasa]

I've just started a build and I'm exclusively using Great Stuff's Pond and Stone. It's not readily available so where I am, I've hoarded pretty much every can I can get my hands on. But do ask your favourite hardware store as they may be willing to order some for you.

This product is everything I was hoping it would be. Bonds rocks securely (do use cable ties though), dries very solid and firm and the colour may be good enough to leave naked for a while until the coralline takes to it.

If you are using the pond spray foam, it is aquarium safe, uv stable, and doesn't appear to break down (I know of some applications that are 5+ years old, I personally have used some for 2+ and it is very durable). There were problems with the spray foam that is basically insulation. Personally I used Beckett's but there are other similar brands.